What happens when you shoot lasers at a dinosaur fossil? Some chemicals preserved in the fossil glow, providing a nuanced portrait of the ancient creature’s bones, feathers and soft tissue such as skin.

Soft tissue is rarely preserved in fossils, and when it is, it can be easily obscured. A technique called laser-stimulated fluorescence “excites the few skin atoms left in the matrix, making them glow to reveal what the shape of the dinosaur actually looked like,” says Michael Pittman, a paleontologist at the University of Hong Kong.

Pittman and colleagues turned their lasers on Anchiornis, a four-winged dinosaur about the size of a pigeon with feathered arms and legs. It lived around 160 million years ago during the Jurassic Period. The researchers imaged nine specimens under laser light and used the photos to reconstruct a model of Anchiornis that shows an exceedingly birdlike body, the team writes March 1 in Nature Communications.

In the crooks of its elbows and wrists, the dinosaur had what looks like taut tissues called patagia, a feature in modern bird wings. “The wings of Anchiornis are reminiscent of the wings of some living gliding and soaring birds,” Pittman says. Plus, the images capture minute details like feather follicles and scales, and confirm some characteristics of Anchiornis long surmised by scientists: that it had drumstick-shaped legs, pads on the balls of its feet and a slim tail.

Still, it’s unclear what geochemicals are actually fluorescing in the fossils because the team didn’t perform any chemical analyses to determine the organic compounds or minerals present. “The images are very cool,” says Mary Schweitzer, a paleontologist at North Carolina State University in Raleigh. But, she cautions, a few hurdles remain, including testing fluorescence in different fossil types and verifying how skin glows under laser light in modern bird fossils.

Scientists normally rely on light-based methods and skeletal data to reconstruct the appearance of dinosaurs and other ancient creatures. Ultraviolet fluorescence works similarly to the new method, but the laser technique captures greater resolution. If laser-stimulated fluorescence lives up to its promise, it could help discern fossilized features that are invisible to the naked eye.

Functional form

Drawing from Anchiornis fossil specimens housed in a Chinese museum, researchers used measurements from laser-stimulated fluorescence images to create a more refined outline of the dinosaur’s body. Numbers in the graphic below correspond to different fossils used to reconstruct specific body parts.

Hover over the dots in the image below to learn more about this dinosaur.